1. Field of the Invention
The present invention relates to a backlight module, and in particular, to a backlight module using a light-emitting diode (LED) as a light source.
2. Description of Related Art
A Liquid Crystal Display (LCD) has advantages of operating under a low voltage, no radiant rays, a light weight and a small size, which a display manufactured by using a conventional Cathode Ray Tube (CRT) does not possess. The LCD has become a main subject of the display study in recent years. Since the LCD is not a self-luminous display, display functions of the LCD are achieved when required light is provided by a backlight module. In recent years, with the improvement of environment protection, a light-emitting element used in the backlight module is transformed from Cold Cathode Fluorescent Lamp (CCFL) to light-emitting diode (LED).
When the LED is applied in the backlight module, e.g., an edge-type backlight module, the LED is usually disposed at a long edge or a short edge of a light guide plate. However, since the products develop towards a trend of being light and thin and lowering the manufacturing cost, the manufacturers manage to use fewer LEDs to achieve the same effect, and the LED is usually disposed at a corner of the light guide plate.
However, the luminance of the LED disposed at a corner of the light guide plate can be achieved only by using the LED with high power. In addition, the LED with high power means that the LED is of a large size to overcome the heat dissipation problem thereof, but the LED in large size is difficult to be disposed at the corner of the light guide plate, thus conflicting with the trend of a light and thin product.